Graphic recording instrument.



R. c. LANPHl EH.

GRAPHIC RECORDING INSTRUMENT. APPLICATION FILED on. 14, 1916.

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Patented Mar. 12, 1918.

PATENT ROBERT C. LANPHIER, OF SPRINGFIELD, ILLINOIS, ASSIGNOR TO SANGAMO ELECTRIC COMPANY, OF SPRINGFIELD, ILLINOIS, A CORPORATION OF ILLINOIS.

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Specification of Letters Patent.

Application filed October 14, 1916. Serial No. 125,726.

To all whom it may concern:

Be it known that I, ROBERT C. LANPHIER, a citizen of the United States, and a resident of Springfield, in the county of Sangamon and State of Illinois, have invented certain new and useful Improvements in Graphic Recording Instruments, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to graphic recording instruments of the type shown and described in an application for Letters Patent filed of even date herewith by Otis Nhite and John Kramer, Serial No. 125,731, in which a record is made on a moving chart by a pen or stylus supported by laterallyswinging arms, the movement of such arms being in response to variations or fluctuations in the actuating force, so that the record made shows such variations or fluctuations. In the instrument shown and described in that application damping magnets are employed to retard the speed of the swinging arms by which the pen is supported, and my present invention has to do particularly with the manner in which such damping magnets are supported. In an instrument of this character it is desirable and important that the damping magnets be so mounted as to be easily removable without disturbing any of the other elements of the instrument, so that a change of magnet strengths may readily be made in calibrating the instrument, or for other reasons, as it is frequently desirable to get a different damping of the moving system, according to the nature of the work in which the instrument is to be used. The object of my invention is to provide an improved construction by which such changes are provided for and made easy. I accomplish this object as illustrated in the drawings and as hereinafter described. That which I regard as new is set forth in the claims.

In the accompanying drawings,--

Figure 1 is a partial front view of the back-plate of the base of a graphic recording instrument such as that shown and described in the said White and Kramer application, and in an application for Letters Patent filed of even date herewith by Otis White and Herbert W. Young, Serial No. 125,730.

Fig. 2 is a partial vertical section on line 2-2 of Fig. 1; and

Fig. 3 is a frontelevation of the removable plate to which the damping magnets are secured.

Referring to the drawings,

el indicates the back-plate of the instrument, which is adapted to be secured to a wall or other suitable support. understood that the remainder of the base is of suitable shape to support the other parts of the instrument, but such other parts are not illustrated as they are not necessary to a clear understanding of my present invention. It may be well to explain, however, that in the instrument referred to there are two laterally-swinging arms connected so as to move in parallelism with each other, and actuated by electrically-operated motor elements similar to the motor element of a mercury motor meter, and consequently two pairs of damping magnets are used, one pair being arranged to coact-with each of the swinging arms, as fully set forth in the said "White and Kramer application.

5 indicates a plate, which, in the construction shown, is substantially rectangular in outline and is adapted to fit in an opening of corresponding shape provided in the upper portion of the back-plate 4, said plate 5 being provided with a marginal flange 6 which fits against the back margin of such opening in the manner shown in Fig. 2. Screws 7 passing through said flange and intothe margin 8 of the back-plate serve to removably secure said plate in position so that it can be readily detached from the rear. 910 indicate damping magnets arranged in pairs upon the outer face of the plate 5, and resting upon vertically-extending ribs 11 which hold the magnets out of contact with the greater portion of the plate and make easier the application of the magnets to the plate, since they are not disturbed by any irregularities in the surface thereof. The magnets are secured to the plate by clamps 12 which extend over the end portions of the magnets and are secured by screws 13 which pass through such clamps and screw into the plate 5, passing through the ribs 11, as best shown in Fig. 2. erably bosses 14 are provided around the holes which receive the screws 13, as shown Pref- Patented. Mar. 12, 1918.

It will be I in Figs. 2 and 3, to provide a more secure engagement for the screws. The magnets 910 are spaced a distance apart in order to provide space between them for a counterbalance weight 15 carried by an arm 16 mounted upon an armature shaft 17 which forms a part of each electrically-operated motor element above referred to, these parts being shown in dotted lines in Fig. 2. The

arrangement is such that as the arms 16 swing in one direction or theother, the

weights 15 will be subjected to the damping effect of the permanent magnets, as pointed out in said i/Vhite and Kramer application. It will be apparent from the foregoing description that when for any reason it is desired to remove the permanent magnets, this may be done by simply remoiing the screws 7 and withdrawing the plates 5 from the rear, the magnets beingtaken away with them without disturbing any of the other parts of the instrument. The magnets may be detached from the plates 5 by simply loosening orreinoving the screws 13 so as to release the magnets from the clamps v12.

That which I claim as my invention, and desire to secure by Letters Patent, is,- 1. In an instrument of the type described, the combination with a base-plate having an opening therein, of a magnet-supporting plate adapted to be applied to said opening from the rear, and a magnetic damping device carried by said magnet-supporting plate. I

2. In an instrument of the type described, the combination with a. base-platehaving an opening therein, of a magnet-supporting plate adapted to be applied to said opening from the rear, damping magnets carried by said magnet-supporting plate, and clamps for securing said magnets in position.

3. In an instrument of the type described, the combination with a baseplate having an opening therein, of a magnet-supporting plate adapted to be applied to said opening from the rear, said plate having 'ribs on its outer surface,- dampii-ig magnets bearing on said ribs, and clamps for securing said magnets on said magnet-supporting plate.

4. In an instrument of the type described, the combination of a base-plate having an opening therein, a magnet-supporting plate adapted to fit in said opening and having a, marginal flange overlying the margin of such opening at the rear, screws passing through said flange and into the margin of said base-plate, and magnets mounted on the outer face of said magnet-supporting plate.

5.- In an instrument of the type described, the combination of a base-plate having an opening therein, a magnet-supportingplate adapted to fit in said opening and having a marginal flange overlying the margin of such opening at the rear, screws passing through said flange and into the margin of said base-plate, and magnets detachably mounted on the outer face supporting plate.

6. In an instrument of the type described, the combination of a base-plate having a opening therein, a magnet-supporting "plate adapted to fit in said opening and having-a inar inal flange overlying the margin of such opening at the rear, screws passing through said flange and into the margin of said base-plate, magnets mounted on the outer face of said magnet-supporting plate, clamps embracing said magnets, and screws extending through said clamps into said magnetsupporting plate for holding said magnets in position.

ROBERT o. LANPHIER.

i @opfilea of this patent, may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, 13. e.

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